1. Field of the Invention:
The present invention relates to a folding machine in a rotary press.
2. Description of the Prior Art:
One example of the known folding machine in a rotary press in the prior art is illustrated in FIG. 5(a). In this figure, successive sheets cut out from a web by means of a pair of rotating cutter drums 10 and 11 are led to a distributor section D as pinched between a pair of conveyor belts 12 and 13, and are alternately distributed therein different directions. The cut sheets distributed in one direction are pinched between another conveyor belt 25 and the conveyor belt 12 on the downstream side of a tapered guide 23 and are conveyed to a rotary runner 34 in a gathering station at the downstream side of the machine. The remainder of the cut sheets distributed in the other direction are likewise pinched between another conveyor belt 26 and the conveyor belt 13 on the downstream side of the tapered guide 23 and are conveyed to a rotary runner 50 at the downstream side of the machine. In this way, the successive sheets cut out by the cutter drums 10 and 11 are distributed alternately in different directions and are gathered at different gathering stations.
The detailed structure of the distgributor section D is shown in FIGS. 6 and 7. On shafts 62 and 63 disposed parallel to each other and simultaneously driven, are mounted guide rolls 19 and 20 for guiding conveyor belts 12 and 13, respectively, and a pair of rotary sheet diverters 60 and 61 disposed coaxially with the guide rolls 19 and 20. These rotary sheet diverters 60 and 61 are respectively provided with protruding cam surfaces 60a and 61a and recessed portions 60b and 61b. In addition, a tapered guide 23 having a pair of diverging sheet guide surfaces 23a and 23b consisting of concave surfaces is provided between the conveyor belts 12 and 13 so as to define diverging routes just downstream of the rotary sheet diverters 60 and 61. Since the rotary guide rolls 19 (20) and the rotary sheet diverters 60 (61) are disposed alternately on the shaft 62 (63), the belt 12 (13) guided by the rotary guide rolls 19 (20) and the cam surfaces 60a (61a) provided on the rotary sheet diverters 60 (61) are adapted to be juxtaposed in the widthwise direction of the sheet.
The distribution of the sheets is carried out in the following manner. When the cut sheets SA and SB (See FIG. 5(b)) are alternately and continuously fed between the rotary sheet diverters 60 and 61 by the conveyor belts 12 and 13, the initial sheet SA is diverted into the flow path formed between the sheet guide surface 23a and the conveyor belt 12 by the protruding cam surface 61a of the rotary sheet diverter 61. Subsequently the sheet SA is delivered into a sheet receiving gap formed by the conveyor belts 12 and 25, and thereafter it is sent to the rotary runner 34 existing on the downstream side as pinched by the belts 12 and 25. In succession, the next cut sheet SB is sent between the rotary sheet diverters 60 and 61, but at this time the protruding cam surface 61a has been rotated to a position outside of the route for the sheet SB and instead the protruding cam surface 60a of the rotary sheet diverter 60 has entered the route for the sheet SB. Hence, the sheet SB is diverted into the flow path formed between the sheet guide surface 23b and the conveyor belt 13, and it is sent to the rotary runner 50 that is different from that for the sheet SA by the conveyor belts 13 and 26. Still further, when the sheet SA subsequent to the last-mentioned sheet SB has been sent to the rotary sheet diverter D, the protruding cam surface 60a has been rotated to a position outside of the route for the sheet SA. Hence, the cam surface 61a again returns into the traveling route for the sheet SA, and the above-described sequence of operations is repeated.
In addition, downstream of the location at which the conveyor belts 12 and 13 are converged by means of a pair of rolls 14 and 15 for the purpose of receiving the successive sheets, they are further guided into parallel routes close to each other by means of rolls 17 and 18, and then they are led into the distributor section D. The conveyor belt 12 is guided to define one route of divergent routes by means of the rotary guide rolls 19 and 20 combined with the distributor section D. And, on the downstream side of the tapered guide 23 conveyor belt 12 defines a closed route jointly with another belt 25 and cooperates therewith to send the distributed sheets to the collecting station. Likewise, after passing through the rotary guide rolls 19 and 20, the conveyor belt 13 cooperates with another belt 26 to send the distributed sheets to the collecting station. In this way, the conveyor belts 12 and 13 form a continuous closed route extending from the position for receiving the cut sheets, through the distributor section D, to the sheet collecting station, further through returning guide rolls and returning to the position for receiving the cut sheets.
However, the cam surfaces in the distributor section in the prior art merely distribute sheets in the diverging space formed by a pair of conveyor belts. They do not have a capability of conveying a sheet while positively holding it. Accordingly, upon passing through the distributor section, a thin paper sheet or a sheet having a small area was liable to be subject to waving, scratching , creasing and paper blocking, and so the reliablity of the prior art device is poor.
Also, since the cam plates and the conveyor belts are juxtaposed in the widthwise direction of the sheets, it is impossible for both the cam plate surface and the conveyor surface to support the sheet edge portions which is a factor causing instability along the width of the sheets. Accordingly, there is a risk that the edge of the sheet may be folded either in the distributor section or in the route between the conveyor belts. Furthermore, since each of the pair of converyor belts is formed of a single belt extending over the route from the position for receiving the cut sheets, through the distributor section and to the sheet collecting station, the belts are compelled to run at a predetermined equal speed over the entire route. Consequently, a waving condition of a sheet generated in the direction of the sheet flow in the space within the diverging belt route before and behind the distributor section would be maintained even at the downstream conveyor belts without being eliminated, and there was a risk that creases would be formed in the sheet in the direction perpendicular to the flow direction.